Quick Answer: How to String a Stihl Weed Eater with Two Holes
To string a Stihl weed eater with two holes, remove the spool head by turning it counterclockwise, measure and cut two equal lengths of trimmer line (typically 21–25 feet depending on your model), insert each line through one hole in the spool, wind both lines in the same direction following the arrow markings on the spool, leave 4–6 inches protruding from each hole, and reassemble by turning the head clockwise until it clicks into place. Ensure both lines are wound evenly with consistent tension.
Understanding Your Stihl Two-Hole Spool Design
A two-hole spool head, commonly found on Stihl AutoCut and PolyCut models, holds two separate lengths of trimmer line instead of one continuous line. This dual-line design has several advantages: it provides more cutting coverage across the trimmer head diameter, ensures one line continues cutting even if the other breaks, and allows for smoother operation since the load is distributed between two lines rather than concentrated on one.
The two holes on your Stihl spool serve as anchor points where the trimmer line is inserted and wound. These holes are typically labeled or marked with arrows indicating the correct winding direction. Understanding this design is critical because improper winding in the wrong direction will cause the lines to unwind during operation or jam inside the head.
What You’ll Need Before You Start
Before beginning the restringing process, gather the following materials and tools:
- Correct trimmer line diameter: Stihl weed eaters typically use .080-inch, .095-inch, or .105-inch diameter line. Check your trimmer’s manual or the spool head itself for the correct specification.
- Trimmer line in the correct length: Most two-hole Stihl heads require 21–25 feet of line total (approximately 10.5–12.5 feet per hole). Some models may vary, so verify your specific model’s requirements.
- Scissors or line cutter: A sharp pair of scissors or a trimmer line cutter to cut the line to exact length.
- Needle-nose pliers (optional): Helpful for removing stubborn old line or manipulating the spool during reassembly.
- Your trimmer’s manual: Keep it nearby for model-specific winding direction and line length specifications.
Having these items ready prevents interruptions and ensures you follow the correct specifications for your particular Stihl model.
How to Remove the Spool Head Safely
Proper spool removal is the foundation of the restringing process. Follow these steps:
- Disconnect the spark plug wire: Before any maintenance, always disconnect the spark plug wire to prevent accidental engine startup.
- Locate the spool head: The spool head is the round rotating part at the end of your trimmer shaft, typically made of plastic with a visible spool inside.
- Turn counterclockwise: Using your hand or a wrench if necessary, turn the spool head counterclockwise. Most Stihl heads unscrew in this direction. Some models have a fixed tab on the shaft; if yours does, press and hold this tab while turning.
- Remove the head completely: Once loosened, the entire head should come off, revealing the spool inside and any remaining old trimmer line.
- Clean out old line: Remove all fragments of the old trimmer line from inside the spool and head. Use needle-nose pliers if pieces are stuck, and wipe the interior clean with a dry cloth.
- Inspect the spool and head: Check for cracks, damage, or wear. If the spool is cracked or the feed mechanism is broken, replacement is necessary rather than restringing.
Measuring and Preparing Your Trimmer Line
Accurate line measurement is essential for proper operation. Incorrect lengths will cause feeding problems or tangling.
Determining correct line length: Consult your Stihl manual for the exact total line length required. For most two-hole models, this is 21–25 feet total. Divide this by two to get the length per hole (typically 10.5–12.5 feet each). Some users find it helpful to mark their cutting length on a tape measure or mark a line on a flat surface to measure against.
Cutting both pieces: Cut two pieces of trimmer line to exactly the same length. Use sharp scissors or a line cutter for clean cuts. Uneven lengths will cause one line to feed before the other, resulting in unbalanced cutting and potential tangling.
Line diameter verification: Before loading the line, confirm it matches your spool’s specifications. Using line that is too thick will jam the head; using line that is too thin will break easily and slip during winding. The correct diameter should slide smoothly into the spool holes without force.
Preparation tip: Some users slightly soften the line ends by briefly holding them near (not in) a flame or hot water. This prevents fraying and makes threading through the spool holes easier, though this step is optional.
Threading and Winding the Line Correctly
This is the most critical step. Incorrect winding direction is the most common cause of restringing failure.
Step 1: Identify the winding direction. Look for arrows molded into the spool indicating the direction to wind. These arrows point in the direction the line should wrap around the spool. If you cannot see arrows, consult your manual for the correct direction—typically clockwise or counterclockwise depending on the model.
Step 2: Insert the first line. Take one prepared length of trimmer line and insert one end into the first hole in the spool. Push it through until approximately 4–6 inches protrude from the hole. This protruding length is critical; it ensures the line feeds properly when the spool is reassembled.
Step 3: Wind the first line. Begin winding the line around the spool in the direction indicated by the arrows. Keep tension on the line with your other hand to ensure it winds evenly and snugly against the spool. Avoid overlapping wraps or leaving gaps. The line should spiral smoothly around the spool in neat, parallel rows.
Step 4: Secure the first line. Most Stihl spools have a notch or groove near the edge where you can tuck the end of the line to hold it in place temporarily. If your spool has this feature, use it. Otherwise, hold the wound line firmly with your hand.
Step 5: Insert and wind the second line. Repeat the process with the second line, inserting it into the second hole and winding in the same direction as the first line. Maintain consistent tension and ensure both lines are wound to approximately the same diameter on the spool.
Step 6: Verify protrusion lengths. Before reassembly, confirm that 4–6 inches of line protrude from each hole. Lines that protrude too little will not feed properly; lines that protrude too much may jam during reassembly or create tangles.
Common winding error: The most frequent mistake is winding one or both lines in the wrong direction. If the arrow shows counterclockwise, winding clockwise will cause the line to unwind when the spool rotates. Always double-check the arrow direction before winding.
Reassembling and Adjusting Tension
Proper reassembly ensures the lines feed correctly and the spool operates smoothly.
Step 1: Position the protruding lines. Before reassembling, ensure both lines are positioned so they exit the spool head through the correct feed holes (usually located on the side or top of the head). The lines should be taut but not under excessive tension.
Step 2: Align the spool. Insert the spool back into the head housing, aligning any alignment tabs or slots. The spool should fit snugly without forcing.
Step 3: Screw the head back on. Turn the spool head clockwise onto the trimmer shaft. Continue turning until you feel resistance—typically when the head is hand-tight. Some Stihl models have a click-lock system that produces an audible or tactile click when properly seated. Listen for this confirmation.
Step 4: Verify the click-lock. If your model has a click-lock mechanism, you should hear or feel a distinct click. If you do not, the head is not fully seated. Unscrew slightly and reseat it. Forcing the head without a proper click can damage the mechanism.
Step 5: Test line rotation. Manually rotate the trimmer head by hand. It should spin freely without resistance or catching. If the lines catch or jam, the head is not properly seated; unscrew and check the line routing.
Step 6: Tap the advance bump. Some Stihl models have an automatic line advance system triggered by tapping a bump on the ground. Once reassembled, lightly tap this bump to advance the lines slightly. This removes excess slack and prepares the trimmer for initial use.
Common Mistakes to Avoid
Winding in the wrong direction: This is the leading cause of restringing failure. The lines will unwind during operation or jam inside the head. Always verify the arrow direction before winding any line.
Using incorrect line diameter: Line that is too thick will jam; line that is too thin will break or slip during winding. Check your manual for the exact specification.
Unequal line lengths: If one line is significantly longer than the other, it will feed before the other, creating unbalanced cutting. Measure both pieces carefully before winding.
Insufficient protruding length: Lines cut too short inside the spool will not feed through the head properly, causing the trimmer to cut with only one line or neither line.
Overlapping or tangled wraps: Sloppy winding creates tangles that jam the spool during operation. Keep tension consistent and wind in neat, parallel rows.
Forcing the head during reassembly: If the head does not screw on smoothly, something is wrong—typically misaligned lines or an improperly seated spool. Stop, unscrew, and troubleshoot rather than forcing.
Forgetting to disconnect the spark plug: Always disconnect the spark plug wire before any maintenance to prevent accidental engine startup.
Troubleshooting If Something Goes Wrong
The spool head will not screw back on. Remove the head and inspect the spool alignment. Verify that both lines are positioned correctly inside the head and not jamming the mechanism. Reposition the lines and try again. If the problem persists, the spool or head housing may be damaged.
The trimmer head will not spin after reassembly. This usually indicates the lines are caught or the spool is misaligned. Unscrew the head, recheck the line routing, and ensure the spool sits completely inside the housing before reassembling.
Only one line is feeding during use. This may indicate the other line is too short inside the spool or improperly wound. Remove the head and verify both lines protrude 4–6 inches from their respective holes. If one line is significantly shorter, you may need to rewind and restring.
The lines keep tangling or jamming. Tangling often results from overlapping wraps or lines wound in inconsistent directions. Remove the head, unwind completely, and restring, paying careful attention to neat, parallel wraps all in the same direction.
The lines break frequently during use. Broken lines may indicate incorrect diameter, uneven winding creating stress points, or excessive tension. Verify the line diameter matches your manual, ensure even winding, and check that the lines are not over-tensioned inside the spool.
The head rattles or feels loose after reassembly. If you hear a click-lock, the head may not be fully seated. Remove and reseat it until you hear the distinct click. If there is no click mechanism on your model and the head still feels loose, it may be stripped; consider replacing the head.
When to Replace the Entire Spool Head
Sometimes restringing is not the solution. Replace the spool head if:
- The spool is cracked or has visible damage.
- The head does not screw on or off smoothly.
- The click-lock mechanism is broken or non-functional.
- The feed holes are damaged or enlarged.
- The lines jam inside the head repeatedly despite correct winding.
- The head is stripped or threads are damaged.
Replacement spool heads are widely available and relatively inexpensive, typically ranging from $15–$40 depending on the model. Replacing a damaged head is often more cost-effective and faster than troubleshooting repeated winding failures.
Frequently Asked Questions
How often should I restring my Stihl two-hole spool?
The frequency depends on usage. Casual homeowners may restring every 1–2 seasons, while frequent users may need to restring every few weeks. You will know it is time when the trimmer no longer cuts effectively or line is visibly worn short.
Can I use any trimmer line, or does it have to be Stihl brand?
You do not need Stihl-brand line, but it must match the correct diameter and type (typically round nylon). Generic brands work fine as long as they meet the specification in your manual. Avoid using line from unknown sources, as incorrect diameter will cause problems.
What if my spool has only one hole instead of two?
Single-hole spools use a different restringing process. Instead of two separate lengths, a single continuous line is wound around the spool, with the midpoint forming the loop that advances. Consult your manual for single-spool winding instructions, as the process differs significantly.
Why does my trimmer line keep unraveling after I restring it?
Unraveling almost always indicates the line was wound in the wrong direction. When the spool rotates, lines wound backward simply unwind instead of staying in place. Verify the arrow direction on your spool and rewind both lines accordingly. If there is no visible arrow, consult your manual for the correct winding direction for your specific model.
Final Thoughts
Restringing a Stihl two-hole weed eater is straightforward once you understand the process and avoid common mistakes. The key points are: verify the correct line diameter and length for your model, wind both lines in the same direction following the spool’s arrow markings, maintain consistent tension, leave 4–6 inches of line protruding from each hole, and reassemble carefully until the spool clicks into place. With these steps, your trimmer will operate efficiently and provide reliable cutting performance.
